Elucidating the Spatial Heterogeneity of Soil Physicochemical Attributes in Three High Arctic Ecosystems.

Approximately 26% of world’s land area is underlain by permafrost; however, in Canada permafrost affected soils comprise 3.7 million km2 or about 40% of the land area. These soil ecosystems differ from others due to long winter, short growing season, frequent cryoturbation and gelifluction. Soil properties are typically heterogeneous as they vary from location to location and a thorough understanding of this spatial variability is imperative to elucidate the complex correlations among the soil processes. In most of the cases, spatial heterogeneity is non-random and tends to decline as distance decreases between points in space. The spatial heterogeneity of soil properties primarily results from topography, predominant vegetation, soil chemical and biological processes. Furthermore, these soil physical and chemical properties are not independent from one another and they operate at multiple spatial scales. Therefore, assessing their scale dependence is also necessary in addition to the geospatial dependency. However, information on spatial scale dependence of soil properties in Arctic ecosystems is extremely limited. In this study we elucidated geospatial and scale dependence of soil physical and chemical properties in three Arctic ecosystems. At each site, 93 soil samples were collected in a variable-lag distance geospatial design. In laboratory, various soil physical and chemical properties were analyzed. Spatial variability of all soil properties and their spatial relationships were determined using geostatistics.